In the realm of quadruped robot locomotion,compliance control is imperative to handle impacts when negotiating unstructured terrains.At the same time,kinematic tracking accuracy should be guaranteed during locomotion....In the realm of quadruped robot locomotion,compliance control is imperative to handle impacts when negotiating unstructured terrains.At the same time,kinematic tracking accuracy should be guaranteed during locomotion.To meet both demands,ajoint space compliance controller is designed,so that compliance can be achieved in stance phase while position tracking performance can be guaranteed in swing phase.Unlike operational space compliance control,the joint space compliance control method is easy to implement and does not depend on robot dynamics.As for each joint actuator,high performance force control is of great importance for compliance design.Therefore,a nonlinear PI controller based on feedback linearization is proposed for the hydraulic actuator force control.Besides,an outer position loop（compliance loop）is closed for each joint.Experiments are carried out to verify the force controller and compliance of the hydraulic actuator.The robot leg compliance is assessed by a virtual prototyping simulation.展开更多
Torque control algorithm and its simulation of capturing a moving target for Free Flying Space Robots(FFSR) are discussed in this paper. The efficient recursive algorithm of joint driven torque for FFSR is developed. ...Torque control algorithm and its simulation of capturing a moving target for Free Flying Space Robots(FFSR) are discussed in this paper. The efficient recursive algorithm of joint driven torque for FFSR is developed. The torque control algorithm combined with Resolved Motion Rate Contro(RMRC) based on Generalized Jacobian Matrix(GJM) for capturing a moving target is proposed. The computer simulation verifies the effectiveness of the proposed algorithm.展开更多
This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. H...This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution （PSODE） is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The co- efficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simulta- neously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method pro- vides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.展开更多
基金Supported by the National High Technology Research and Development Program of China(863 Program)(2011AA041002)
文摘In the realm of quadruped robot locomotion,compliance control is imperative to handle impacts when negotiating unstructured terrains.At the same time,kinematic tracking accuracy should be guaranteed during locomotion.To meet both demands,ajoint space compliance controller is designed,so that compliance can be achieved in stance phase while position tracking performance can be guaranteed in swing phase.Unlike operational space compliance control,the joint space compliance control method is easy to implement and does not depend on robot dynamics.As for each joint actuator,high performance force control is of great importance for compliance design.Therefore,a nonlinear PI controller based on feedback linearization is proposed for the hydraulic actuator force control.Besides,an outer position loop（compliance loop）is closed for each joint.Experiments are carried out to verify the force controller and compliance of the hydraulic actuator.The robot leg compliance is assessed by a virtual prototyping simulation.
文摘Torque control algorithm and its simulation of capturing a moving target for Free Flying Space Robots(FFSR) are discussed in this paper. The efficient recursive algorithm of joint driven torque for FFSR is developed. The torque control algorithm combined with Resolved Motion Rate Contro(RMRC) based on Generalized Jacobian Matrix(GJM) for capturing a moving target is proposed. The computer simulation verifies the effectiveness of the proposed algorithm.
基金supported by the National Natural Science Foundation of China (11072122)
文摘This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution （PSODE） is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The co- efficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simulta- neously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method pro- vides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.
